Toggle switch swing arm



Dec. 13, 1955 HUBBELL 2,727,107

TOGGLE SWITCH SWING ARM Filed Aug. 9, 1950 2 Sheets-Sheet 1 54 Q 35 36 F 2;: w 55 a ,3

Snnenfor M W (Ittornegs Dec. 13, 1955 HUBBELL 2,727,107

TOGGLE SWITCH SWING ARM Filed Aug. 9, 1950 I 2 Sheets-:Sheet 2 21' 3nventor 48 my i M Gttomegs United States Patent TOGGLE SWITCH SWING ARM Harvey Hubbell, Long Hill, Conn.

Application August 9, 1950, Serial No. 17 8,397

6 Claims. (Cl. 200-67) This invention relates to electric switches, and more particularly to toggle switches of the type in which a circuit closing contact arm is connected to a spring stressed pivoted yoke member which is actuated by a swing arm to alternately snap the yoke and contact arm into on and off positions.

In operating this type of switch the yoke and the yoke operating swing arm strike against adjacent confining portions of the switch housing, at the ends of their movements in each direction, resulting in the usual noisy click whenever the switch is operated. An object of this invention is to provide a toggle or similar type switch having an improved construction providing a substantially silent operation.

A further object is to provide an improved arrangement for mounting the contact arm of a toggle switch, or the like, on the arm operating yoke.

A further object is to provide an improved construction of mounting for connecting the contact arm of a toggle switch to the arm actuating yoke, of such character as not only to silence the operation thereof but also increase the speed with which the switch contacts are separated to produce a quick breaking of the associated circuit.

With the foregoing and other objects in view, I have devised the construction illustrated in the accompanying drawings forming a part of this specification. It is, however, to be understood the invention is not limited to the specific details of construction and arrangement shown, but may embody various changes and modifications within the scope of the invention.

In these drawings:

Fig. 1 is a section through a toggle switch constructed in accordance with one embodiment of the invention;

Fig. 2 is a top plan view of the switch shown in Fig. 1;

Fig. 3 is a transverse section thereof;

Figs. 4 and 5 are side and top views, respectively, of the current-controlling contact arm and operating yoke showing in enlarged scale the mounting for the arm on the yoke as employed in Figs. 1, 2 and 3;

Fig. 6 is a front elevation of the yoke showing in section one form of resilient mounting for .connecting the contact arm to the yoke;

Fig. 7 is a top plan of a portion of the yoke shown in Fig. 6;

Figs. 8 and 9 are front and end elevations of the resilient bushing employed in the construction shown in Figs. 1 to 6;

Fig. 10 is a section similar to a portion of Fig. 1 of a modified switch construction;

Figs. 11, 12 and 13 are top, side and front elevations, respectively, of a yoke and associated contact arm provided with a modified form of arm-supporting bushing;

Fig. 12a is a front view of the central portion of the contact element of Figs. 11 to 13 showing the shape of the opening therein;

Figs. 14 and 15 are side and top views of a modified form of contact arm;

Fig. 16 is an end view thereof;

Fig. 17 is a section on the line 1717 of Fig. 14;

Figs. 18 and 19 are front and side elevations of one part of the bushing shown in Figs. 11, 12 and 13;

Fig. 20 is a section similar to Fig. 10 of a further modification of the invention, and

Fig. 21 is a section showing a still further detail.

The illustrated embodiment of the invention is shown as a toggle switch having a housing or body 25 formed by a base portion 26 of insulating material and a cover portion 27 removably secured to the base portion by any suitable fastening means such as screws 28 or the like, which also secure a mounting strap or yoke 29 to the cover 27. The body therefore comprises the upper and lower body sections 27 and 26. As illustrated, the switch includes the usual stationary contacts 31 (those shown being spring contacts comprising opposed U-shaped spring fingers 31a) supported at opposite ends of a chamber 32 in the base 26 adapted to be connected electrically by an oscillatory contact arm 33 when in one position and to be disconnected when the arm is in its other position. Guides 34 are provided in the chamber 32 on opposite sides of the contact arm 33 for guiding the movement thereof. The contact arm 33 is mounted on an oscillatory arm 35 forming part of a U-shaped yoke 36 pivoted on the base portion 26 on arms 35, 37, the arm 35 including pivot portion 37a and being extended across the chamber 32 to support the contact arm 33 in line with the contacts 31. This arm is provided with the flattened portion 55 presently to be described. A switch actuating swing arm or handle 38 is pivoted on a supporting stud 39 or the like in bearing recesses 41 in the base 26 and recesses 42 in the cover 27. The fulcrum of the handle is therefore held between the upper and lower body sections. A yoke-operating spring 43 is compressed between a round spring-engaging lug 44 on the inner end of the swing arm 38 and a spring-retaining hump 45 on the yoke 36, so that as the arm 38 is swung in one direction or the other and the lug 44 crosses the center line between the lug and the hump 45 on the yoke 36, the spring 43 snaps the yoke to the opposite side, thus oscillating the contact arm to alternately connect and disconnect the contacts 31. The yoke 36 is pivotally mounted by the pivot portions 37 and 37a seating in open recesses 26b in side wall 26a, and 260 in partition wall 26a of the base section of the body.

As these switches have heretofore been constructed, the swing arm has shoulders 46 which normally strike the upper edges of partition walls 47 at each end of its movement, and the movement of the yoke 36 is limited by striking the inner faces of such partitions, producing the loud noisy click usually heard upon each operation of the switch.

in the present invention the noise of operation is substantially eliminated by means of inserts 4% of suitable resilient material such, for example, as rubber or plastic, natural or synthetic. As illustrated on the left in Fig. i, an insert 48 is mounted in a recess 49 and forms a liner along the face of the partition 47 in position to act as a bumper or cushion at its upper end 43b for the shoulders 46 on the swing arm 38, and its inner side walls as]; also act as a bumper for the lower end of the pivoted yoke 36 to silence and reduce the jar of operating a snap switch.

A somewhat different arrangement is shown on the right of 1 where the insert 43:: is anchored to the bottom of the base portion 26 by means of a button 53 or the like on the bottom edge of the insert 48:: extending through an opening 52 in the lower Wall 53 of the base portion 26, for the purpose of firmly anchoring the insert 454: in place. The upper end am of ele ment 4% acts as a bumper for shoulder 46a on the handle and its inner wall 48a acts as a bumper for the yoke 36.

A further modification is shown in Fig. in which a pair of resilient rivets 48f of rubber or other cushioning material are mounted on opposite sides of the yoke 36 in openings 53a in the lower wall 53 in position to engage the swinging end of the yoke 36 and form resilient stops against which the yoke strikesv Operation of the switch is further silenced and that of the contact arm is improved by resiliently mounting the contact arm on the oscillatory shaft of the yoke 36. The shaft 35 has a noncircular section 54 shown in Figs. 6 and 7, for example, as a flat diametral flange 55. A bushing 56 of rubber or other resilient insulating material and of oval or other noncircular shape has an axial opening 57 with slots 58 at each side thereof to receive the edges of the flange and be held on the shaft 35 against relative rotation. A groove 59 in the periphery of the bushing 56 receives the edge 61, see Fig. 9, of an oval opening 62 in the contact arm 33. This bushing is preferably made somewhat larger than the opening 62 so that in mounting it in the opening it must be compressed somewhat or preloaded.

As illustrated in Figs. 11 to l3, l8 and 19, the bush ing can be in split form having two similar sections 64, each having a notch 65 in the fiat side 66 thereof, and an external groove 67 similar to the groove 59 in the one-piece bushing 56. The two sections 64 are inserted in opposite sides of the oval opening 62a in the contact arm 33 with the flat diametral flange 55 inserted in the notches 65, as shown in Fig. 11.

As shown in Fig. 12, the oval opening 62a in the contact arm 33 receiving the bushing is formed with a rectangular central portion 6% extending transversely to the length of the arm, thus forming rectangular recess 68a on opposite sides of the central portion of the opening 6211 between the curved end portions 6212 as shown more clearly in Fig. 12a. This arrangement facilitates assembly and disassembly of the parts. The bushing sections 6-4 are seated in the curved end portions 62b of the opening 62a and are held therein by the flattened flange portion 55 of the shaft portion 35 of yoke 36, as shown in Figs. 11 and 12.

Application of the invention to a different construction of contact arm or member is illustrated in Figs. 14 to 17, in which the arm is formed by two spring members 71 placed side by side and having diverging edge flanges 72 on the upper and lower edges at each end of the members 71, whereby to form notches 73 between the flanges to receive the edge of a knife type stationary contact member in the switch (not shown). The two members 71 are held together securely by a resilient bushing 74 which can be of the same general construction as the bushing 56 shown in Fig. 6.

Fig. 21 illustrates a still further form of bushing for mounting the contact arm 33 on the yoke shaft 35 in which a bushing 76 has an outer shoulder 77 formed by an inner noncircular or oval portion 73 of less diameter and an outer portion 79 of larger diameter, the arm being mounted on the smaller portion 78 against the shoulder 77 by a similarly shaped, as oval, opening in the arm, which properly locates the arm relatively to the yoke 36 and the contacts 31. This bushing also acts as a spacing means between the contact arm and the inner wall 26a of the body.

In all forms the resilient bushing for mounting the movable contact member is preferably prestressed or pre loaded as described in connection with bushing 56.

In operation, the bumpers, either of the type shown in Fig. 1 or that shown in Fig. 20, for example, provide silencing stops for the pivoted yoke 36. With the type of inserts 48 shown in Fig. 1, operation of the swing arm 38 is also silenced by the shoulders 46 on the swing arm 38 engaging the tops of the resilient inserts,

with the result that a practically silent switch operation is obtained.

Also, the resilient bushings 56, 64, 74, 76 connecting the contact arms 33 or 71 to the yoke arm 36 both reduce the noise of operating the switch and provide a resilient support for the arm 33 or 71 which is of such form as to produce an improved action on the part of the contact arm. Due to frictional engagement between the contact arm 33 or 71 and the stationary contacts 31, or contacts cooperating with arm 71, the resilient bushing material is stressed and distorted by the preliminary movement of the yoke 36 at which time there is little or no movement of the contact arm, which is frictionally restrained by its engagement with the associated contacts 31 or the like. As the yoke moves further suflicient force is applied to the arm through the resilient bushing 56 to cause the latter to snap the arm quickly away from the contacts 31 with a quick circuit-breaking action. Thus the resilient bushing causes a delayed action and cooperates with and supplements the action of the toggle spring 43 to' give a quicker break between the movable and stationary contacts and reduce arcing.

The invention can be variously modified and adapted within the scope of the appended claims.

Having thus set forth the nature of my invention, I claim:

1. The combination in a toggle switch having a springstressed yoke pivoted for movement between two positions, a yoke operating swing arm, and a contact arm provided with an elongated opening, of means connecting said contact arm to said yoke comprising an axial supporting shaft on said yoke having a flat diametral section, a yieldable resilient insulating bushing mounted in the elongated opening through said contact arm and including longitudinally separated oppositely disposed sections having longitudinal facing slots on the inner faces thereof receiving the opposite edges of said flat diametral shaft section and peripheral grooves in their outer walls forming seats receiving the edges of said opening in said contact arm, said shaft retaining the bushing sections against the edges of the opening with these edges seated in the grooves, and said bushing forming the sole means of mounting the contact arm on the shaft.

2. The combination in a toggle switch having a springstressed yoke pivoted for movement between two positions, a yoke operating swing arm, stationary contacts, and a movable contact arm provided with a non-circular opening and movable to and from sliding engagement with the stationary contacts whereby the movable contact arm is frictionally held by the stationary contacts against separation therefrom, of means connecting said contact arm to said yoke comprising an axial supporting shaft on said yoke having a flat diametral section, a yieldable resilient insulating bushing mounted in the opening through said contact arm and having a diametral elongated slot nonrotatably engaging said fiat section on said shaft, and an outer surface having a portion of lesser size forming a seat engaging in the opening in said contact arm and a portion of greater size forming a shoulder engaging the side face of said contact arm to position said arm relatively to said yoke, and said bushing forming the sole means of mounting the contact arm on the shaft and yieldable to permit limited relative movement between the shaft and contact arm and allow the contact arm to be held a short time by the frictional engagement between the contacts during initial movement of the yoke and cause delayed separation of the movable contact arm from the stationary contacts.

3. The combination in a toggle switch having a springstressed yoke pivoted for movement between two positions, a yoke operating swing arm, stationary contacts, and a movable contact arm provided with a non-circular opening and movable to and from sliding engagement with the stationary contacts whereby the movable contact arm is frictionally held by the stationary contacts against separation therefrom, of means connecting said contact arm to said yoke comprising an axial supporting shaft on said yoke having a non-circular section, and a yieldable resilient insulating bushing mounted in the opening through said contact arm and provided with a non-circular section in its peripheral surface provided with a seat in which the edges of the opening in the contact arm are seated, and said bushing having a noncircular opening in which said non-circular section on said shaft is seated, the said bushing forming the sole means of mounting the contact on the shaft and yieldable to permit limited relative movement between the shaft and contact arm and allow the contact arm to be held a short time by the frictional engagement between the contacts during initial movement of the yoke and cause delayed separation of the movable contact arm from the stationary contacts.

4. The combination in a toggle switch having a springstressed yoke pivoted for movement between two positions, a yoke operating swing arm, stationary contacts, and a movable contact arm provided with a non-circular opening and movable to and from sliding engagement with the stationary contacts whereby the movable contact arm is frictionally held by the stationary contacts against separation therefrom, of means connecting said contact arm to said yoke comprising an axial supporting shaft on said yoke having a flat diametral section, and a yieldable resilient insulating bushing mounted in said opening through said contact arm and provided with a non-circular outer portion forming a slot on which the edges of said opening are seated, said bushing having a diametral slot non-rotatably engaging said flat section on said shaft to mount the bushing thereon, said bushing forming the sole means of mounting the contact arm on the shaft and yieldable to permit limited relative movement between the shaft and contact arm and allow the contact arm to be held a short time by the frictional engagement between the contacts during initial movement of the yoke and cause delayed separation of the movable contact arm from the stationary contacts.

5. A toggle switch comprising stationary contacts, a pivotally mounted yoke, a movable switch contact mounted on said yoke provided with a non-circular opening and movable to and from sliding frictional engagement with the stationary contacts whereby the movable contact is frictionally held by the stationary contacts against separation therefrom, a yieldable resilient insulating bushing mounting having a non-circular outer portion seated in the opening in the contact and mounted on the movable contact on the yoke, said bushing forming the sole means of mounting the contact on the yoke and yieldable to permit a limited relative movement between the yoke and contact and permit the movable contact to be held a short time by the frictional engagement between the contacts during initial movement of the yoke to cause delayed separation of the movable contact from the stationary contact on operation of the yoke, and means for operating the yoke.

6. The combination in a toggle switch having a springstressed yoke pivoted for movement between two positions, a yoke operating swing arm, stationary contacts, and a movable contact arm provided with a non-circular opening and movable to and from sliding frictional engagement with the stationary contacts whereby the movable contact arm is frictionally held by the stationary contacts against separation therefrom, of means connecting said contact arm to said yoke comprising an axial supporting shaft on said yoke having a non-circular section, a yieldable resilient insulating bushing mounted in the opening in the contact arm provided with a peripheral groove in its outer surface forming a seat in which the edges of the opening in the arm are seated, and said bushing being mounted on the noncircular section of said shaft and forming the sole means of mounting the contact arm on the shaft, said bushing being yieldable to permit limited relative movement between the shaft and contact arm and allow the contact arm to be held a short time by the frictional engagement between the contacts during initial movement of the yoke and cause delayed separation of the movable contact arm from the stationary contacts.

References Cited in the file of this patent UNITED STATES PATENTS 1,796,854 Millermaster Mar. 17, 1931 1,817,234 Butler et al. Aug. 4, 1931 1,821,180 Gaynor Sept. 1, 1931 2,209,382 Blattner July 30, 1940 2,269,171 Benander Jan. 6, 1942 2,579,523 Terry Dec. 25, 1951 FOREIGN PATENTS 483,840 Great Britain Apr. 27, 1938 521,612 Great Britain May 27, 1940 620,633 Great Britain Mar. 28, 1949 

